1. Field of the Invention
This invention relates generally to robotic loader systems, and more particularly, to a two-axis arrangement for loading, unloading, and transferring articles between conveyor stations.
2. Description of the Related Art
Arrangements for loading and unloading articles between conveyor systems, or between containers and conveyor systems typically are expensive and complex. Generally, an overhead transport arrangement is employed to transfer the articles between the unloading and loading stations. For example; a mechanical gripper engages one or more articles at the unloading station; transports same in a first direction, typically upward, to clear the container, conveyor, or other mechanisms; utilizes the overhead transport arrangement to deliver the articles by horizontal travel to a location over the loading station; and transport the articles in a second direction, typically downward, into another container or conveyor at the loading station. Clearly, significant overhead structure, sufficient to span both stations, is required in this conventional arrangement. Programming of a variety of parameters, such as trolley travel distance, acceleration, etc., is required in an automated version of such an arrangement.
Such arrangements are generally quite massive and do not lend themselves to modifications in the manufacturing layout. The transom, or crane runway portion of the apparatus is fixed in its length, and is not readily movable. No variation in the path is permitted.
In addition to the foregoing, an overhead trolley arrangement poses problems with respect to cleanliness, particularly in areas where airborne matter is to be prevented. More specifically, it is difficult to enclose an elongated overhead trolley and track arrangement. This problem is compounded by the fact that the wheels or rollers of the trolley are continually wearing and require periodic lubrication. An overhead trolley arrangement can disperse lubricants and particles into the air, and will collect dust which can be released when the trolley is moved.
There is, therefore, a need for an arrangement for loading and unloading articles which does not require the use of massive or extensive overhead structure.
It is additionally a problem with trolley or shuttle arrangements that, as the rows of a container are loaded, the length of travel of the trolley must be incremented by a distance which corresponds to a dimension of the article(s) being loaded. Thus, a relatively massive combination, i.e., trolley and article, must be moved over incrementally varying distances, requiring a programmable high-powered motor arrangement. Such an arrangement is both, complex and expensive. In order to improve operating speed, it is necessary to employ motors rated for higher continuous power levels, and to strengthen the track on which the trolley travels and its associated support structure in view of the increased operating loads and accelerations.
It is, therefore, an object of this invention to provide a simple and inexpensive loading and unloading arrangement wherein articles such as bottles can be transferred between a container, on a container conveyor, and a transfer station on an article conveyor.
It is another object of this invention to provide a loading and unloading arrangement which transfers articles between at least to transfer stations without the need of a transfer trolley.
It is also an object of this invention to provide a loading and unloading arrangement which does not employ extensive or complex structure disposed over the loading or unloading stations. It is a further object of this invention to provide a loading and unloading arrangement wherein the moving parts and their associated bearings can readily and effectively be sealed.
It is additionally an object of this invention to provide a loading and unloading arrangement which can be utilized in an automated environment with reduced complexity of control system programming.
It is yet a further object of this invention to provide a loading and unloading arrangement which requires less maintenance than systems which employ overhead shuttle trolleys.
It is also another object of this invention to provide an unloading arrangement for removing articles from a container.
It is yet an additional object of this invention to provide a loading and unloading arrangement for unloading articles from a container and loading the articles onto a conveyor.
It is still a further object of this invention to provide a loading and unloading arrangement wherein the work which otherwise would be required to be performed by a trolley motor can be divided over several less powerful motors.